Samisoni Kanongata’a
Lecturer, Tonga Institute of Science and Technology School of Agriculture

The Tongan farming system is essentially an agro-forestry system of bush or grass fallow with cultivated coconut palms and other useful trees such as Bischovia javanica (used in the coloring and dying of tapa cloth), Santalum yasi (used in sandalwood perfume), Artocorpus altilis (breadfruit fruit trees) and Morinda citrifolia (used for medicinal purposes) creating a multi-story system for multiple cropping. The traditional staple crops of yams (Dioscorea spp), taro (Colocasia esculenta), sweet potato (Ipomoea batatas) and cassava (Manihot esculenta) dominate agricultural production and household consumption. Tongans have evolved a highly productive complex farming system which exploits good soils and climate without fertilizer. Basically, the traditional Tongan farming system is one main cropping cycle but was highly modified by Tongan forefathers to suit individual preferences, food security, nutritional requirements, and sustainability and meet sociological obligations.

Indigenous Knowledge

Despite the success of modern techniques, it is important to consider the indigenous knowledge of smallholder farmers, which affect some of the decisions they make and methods they practice.

Thrupp (1989) notes the increasing attention given to the indigenous knowledge and capabilities of small scale framers in developing countries as a potential basis for sustainable agricultural development. Rural people have a good understanding of their resources and often are adept at experimenting and adapting to changes over time. Numerous analysts have discussed the knowledge, practices, indigenous skills, and beliefs of the rural farming population in developing countries. These insights and adaptive skills of farmers are often derived from many years of experience and may be called cultural traditions.

Figure 1. Three main moon phases.

In general, they have learnt through observation and practical experiences through family members and/or elders in the community. Obviously, decisions to use these ideas are not based on empirical measurement or cost benefit analyses as in conventional modern science. Farmers in many parts of the world use their knowledge of lunar cycles as a basis for farming, fishing, and other cultural practices. Tongan smallholders in ancient times had their own calendar around which farming activities revolved. As days all looked the same, the nights were used to mark time through the phases of the moon, from the time it rose, and the change of phases. The year comprised of thirteen lunar months where each lunar month consisted of twenty-eight days. Within each month the moon is considered to go through three different phases as shown in figure 1.

The month began with a thin crescent of the new moon and was first visible at sunset. It took twelve days from the point of moonrise to the point of displaying a full moon, and another twelve days to moon set. The moon disappeared for a period of four to five days before rising again.

The Tongan calendar is significant in agricultural activities and decisions that smallholders make in terms of timing and productivity. The passage of the year is generally marked by reference to months of the year and the two main seasons. The names of the months in the Tongan calendar were based on the relative growth and development of yam cultivation, the most valued of the food crops in Tonga. Broadly, the moon phases stated that there are naturally advantageous times to plant certain crops, as well as to weed and prepare land.

A key informant pointed out that “the principle of achieving maximum results with minimum effort is still reflected in our lunar calendar”, which stressed that the importance of performing the right activity at the right time was more productive. The best time of the month to plant crops is determined by the phase of the moon. Crops are said to grow best if planted between the period of moonrise and full moon, whereas weeding is best performed when the moon starts to phase out. The period of the four to five days between the setting of the moon and its rise normally known as “the disappearing of the moon” is considered the best time for land or seedbed preparation and preparation of planting materials. Smallholder farmers normally set out their farm work program accordingly. As some asserted “we never plant our root crops beyond the full moon phase or when the moon is weak, as we will receive low yields, and we never weed before the full moon phase when the moon is strong, as it is hard to kill weeds during this time.” It is evident that some rural farmers know the basic calendar and still operate accordingly to some extent.


Halavatau, S.M., Key Issues Affecting Sustainable Land Management in the Kingdom of Tonga, 1998.

Havea, L., Field Survey on Agricultural Technology – Transfer – in Tonga, 1998.

Hoponoa T., Agro forestry System in Tonga, et al., 1991.